Cadmium plating of 15-5PH Steel

A discussion started in
2006 & continuing through 2017

(2006)

Q. During the process of post backing of 15-5 PH steel, if the electric supply failure occurs, then what can we do wether we start the post backing process from beginning or we can start it from onward after the availability of electric supply?

Amir Sohail- Karachi, Sindh, Pakistan

(2006)

A. Hi Amir. In general, neither is acceptable. Hydrogen de-embrittlement is a time-sensitive process that must be completed before the hydrogen damages the steel. If the steel is damaged due to the hydrogen not being removed soon enough, it's been damaged and embrittlement relief later will not work.

Ted Mooney, P.E. RETfinishing.comPine Beach, New Jersey

(2007)

Q. Dear sir,
We are also doing non cyanide cadmium plating as per BAC 5701. Problem we are facing is this: when we do plating it swells at once as we apply current. The pH of bath when we made it was 8 to 9. At that time plating was ok. Now when we added further cadmium oxide with HCl to clear the slurry, then its pH decreases. After this addition we faced problem. Can anybody tell me pH can effect cadmium plating so it swells, or there is any other reason? And how I can correct it.

IFTIKHAR ALI PIAC - PAKISTAN

(2007)

A. What do you mean by "the plating swells"?

Also, as I remember, acid cad is not normally made up with HCl as the acid. Brighteners and levelers are very tricky for this bath and is why it has virtually gone out of commercial use.

James Watts- Navarre, Florida

(2007)

Q. Dear James,
Thanks for your reply. In fact my problems are:
1- we are doing non cyanide cadmium plating with requirement of 10-20 amperes per square feet.
When we do plating on part of 15-5 PH steels we experience burning on the lower edge of part. In addition the part edges become sharper and small particles begin to gather during plating. These particles are some metal in type. Due to sharp edges formation like burrs appears which are not acceptable to customers. Please help me in this regard.
2- for gaining 10 amperes square feet or above we have to give voltage at 14 volts are higher due to high voltage racking wire become hot and burning appears. What should we do?
Please guide me as soon as possible.
waiting for your reply.

A. Hi IFTIKHAR. You apparently are experiencing "burning". Your racking wires are surely too few or too small if they are getting hot and you need 14 volts to get 10 ASF. In short, the parts have to be properly racked. You might consult the racking chapter in the Electroplating Engineering Handbook if you have no racking experts available to help. Good luck.

Q. Hi,
I need your support/help.
First I introduce myself, I am T.Chandra Sekhar Reddy, Plating shop employee in a Corporate Organization in Mumbai, India. We are following the Standard QQ-P-416 [link by ed. to spec at Defense Logistics Agency, dla.mil]
for Cadmium Plating. We don't have any problem in processing of 4130/ 4340 materials. But we are facing problems in processing of 15-5 PH Steels.
I would like to take your suggestions/guidance to overcome the following issues.
1. Blisters observed in Cadmium Plating. What are the possible reasons for blisters in cadmium Plating. (Pre cleaners are cleaned once in a week. Cadmium plating bath filter cleaned every week.)
2. What are the impurities to be checked in Cadmium plating bath.
3. Components requiring cadmium plating on external surfaces only. Presently we are masking with Teflon tape and maskant Turcofoam-522. Masking with Teflon tape and maskant Turcofoam-522 is time consuming process and productivity is low. I want to mask with Rubber/ plastic caps, which are competent with our plating baths (Alkaline based pre cleaners/ Ferric Chloride+ HCl/ Nickel Strike/ cyanide based Cadmium bath.)
I am waiting for your golden suggestions, which can give improvements in my process/ productivity w.r.t. Quality and Quantity.

A. Blisters, if they are very tiny but lots of them, frequently result from over cleaning/etching. Larger blisters or peeling frequently results from under cleaning/etching.
I would try a few with less cleaning and check for a water break and then see if they pit. If they do, clean/etch for a longer time and see if you get blisters this way.
It might require a different etch since it is a stainless equivalent vs the chrome/iron/carbon in the steels. Ferric chloride is a very aggressive etch, especially as it builds up contaminates. If the above failed,try a few parts in the lab with virgin cleaning/etch materials.

James Watts- Navarre, Florida

A. Hi T. Chandra. My suspicion is that the problem is in the nickel strike rather than the cadmium plating: first, because if the strike is okay, the cadmium bath is looking at nickel plated parts and shouldn't "care" whether the substrate underneath the nickel was 4130, 4340, or 15-5 PH. And second because 4130 and 4340 have little chrome in them, thus are not being especially hard to activate, whereas 15-5 PH has more that 10x as much chrome and is difficult to activate. It seems possible that a marginal nickel strike easily activates 4130 and 4340 while failing to properly activate 15-5 PH.

Simple vinyl caps and plugs should be fine for temperatures up to about 150 °F; above that you may need silicone caps and plugs. Good luck.

Regards,

Ted Mooney, P.E. RETfinishing.comPine Beach, New Jersey

January 30, 2017 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. Is it possible to plate Cadmium on 15-5PH stainless steel?

SIMHA NADIR - ISRAEL

January 2017

A. Hi Simha. Yes it is possible, but people report adhesion problems ... so we appended your inquiry to a thread on the subject. Good luck.

Is H2 embrittlement relief required for cad plated 15-5 PH?

March 10, 2017 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. I work in Quality department of a manufacturer that produces aluminum components for aerospace industry. I have received some bushings made from 15-5PH. As per MPS 160-8, bushings require cadmium plating, type 2, class 3 on OD, undercut and ID. Does it require hydrogen embrittlement relief (hydrogen de-embrittlement baking)? Please advise. Thank you.

Afzal Shahid - Mississauga, ON, Canada

March 2017

A. Hi Afzal. As you see, we added your question to an existing thread on the subject, which implies that the answer is: "Probably". Good luck.

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